Nigerian gunmen who kidnapped a Canadian woman in the northern city of Kaduna say she is seriously ill, but insist on the payment of a $136,000 ransom before she is freed.

A man who answered a phone being used by the kidnappers told VOA the Canadian woman kidnapped last week is seriously ill. "She is very, very bad. The situation is getting worse every day. There are rashes all over her body. There is no doctor. She says she cannot take medication in Nigeria. She needs her drugs," he said.

Whether the 45-year-old Canadian woman really needs urgent medical attention or if it is just a bargaining ploy could not be ascertained.

Julie Ann Mulligan was in Nigeria, with four others, on a Rotary exchange program when she was abducted by armed men who blocked the vehicle she was traveling in.

Nigerian police say the kidnappers are demanding a ransom of about $136,000. The unidentified man said Mulligan would not be released unless the ransom was paid. "As soon as the money is paid. As soon as you people pay the money, she will be released," he said.

The man sounded reasonably educated, young and self-assured. When asked why he and his group will not release the married mother of two due to her failing health, he said, "I do not know. I really do not have anything to say about that."

Kidnappings for ransom, mainly of oil workers, occur regularly in the southern oil-rich Niger Delta. Mulligan's case was believed to be the first of its kind in the mainly Muslim northern Nigeria .

Authorities in the north are reluctant to pay the ransom as this could trigger a wave of kidnappings across the region, where poverty and unemployment are rife, despite billions of dollars earned annually by Nigeria through oil sales.

The United States Agency for International Development says more than 70 percent of Nigerians live on less than a dollar a day, and the population is among the 20 poorest in the world.